new CSV file processing module - see PEP 305

5 files changed, 2504 insertions, 0 deletions

diff --git a/Doc/lib/libcsv.tex b/Doc/lib/libcsv.tex
new file mode 100644
index 0000000..283e401
--- /dev/null
+++ b/Doc/lib/libcsv.tex
@@ -0,0 +1,281 @@
+\section{\module{csv} --- CSV File Reading and Writing}
+
+\declaremodule{standard}{csv}
+\modulesynopsis{Write and read tabular data to and from delimited files.}
+
+\versionadded{2.3}
+\index{csv}
+\indexii{data}{tabular}
+
+The so-called CSV (Comma Separated Values) format is the most common import
+and export format for spreadsheets and databases.  There is no ``CSV
+standard'', so the format is operationally defined by the many applications
+which read and write it.  The lack of a standard means that subtle
+differences often exist in the data produced and consumed by different
+applications.  These differences can make it annoying to process CSV files
+from multiple sources.  Still, while the delimiters and quoting characters
+vary, the overall format is similar enough that it is possible to write a
+single module which can efficiently manipulate such data, hiding the details
+of reading and writing the data from the programmer.
+
+The \module{csv} module implements classes to read and write tabular data in
+CSV format.  It allows programmers to say, ``write this data in the format
+preferred by Excel,'' or ``read data from this file which was generated by
+Excel,'' without knowing the precise details of the CSV format used by
+Excel.  Programmers can also describe the CSV formats understood by other
+applications or define their own special-purpose CSV formats.
+
+The \module{csv} module's \class{reader} and \class{writer} objects read and
+write sequences.  Programmers can also read and write data in dictionary
+form using the \class{DictReader} and \class{DictWriter} classes.
+
+\note{The first version of the \module{csv} module doesn't support Unicode
+input.  Also, there are currently some issues regarding \ASCII{} NUL
+characters.  Accordingly, all input should generally be plain \ASCII{} to be
+safe.  These restrictions will be removed in the future.}
+
+\begin{seealso}
+%  \seemodule{array}{Arrays of uniformly types numeric values.}
+  \seepep{305}{CSV File API}
+         {The Python Enhancement Proposal which proposed this addition
+          to Python.}
+\end{seealso}
+
+
+\subsection{Module Contents}
+
+
+The \module{csv} module defines the following functions:
+
+\begin{funcdesc}{reader}{csvfile\optional{,
+                         dialect=\code{'excel'}\optional{, fmtparam}}}
+Return a reader object which will iterate over lines in the given
+{}\var{csvfile}.  \var{csvfile} can be any object which supports the
+iterator protocol and returns a string each time its \method{next}
+method is called.  An optional \var{dialect} parameter can be given
+which is used to define a set of parameters specific to a particular CSV
+dialect.  It may be an instance of a subclass of the \class{Dialect}
+class or one of the strings returned by the \function{list_dialects}
+function.  The other optional {}\var{fmtparam} keyword arguments can be
+given to override individual formatting parameters in the current
+dialect.  For more information about the dialect and formatting
+parameters, see section~\ref{fmt-params}, ``Dialects and Formatting
+Parameters'' for details of these parameters.
+
+All data read are returned as strings.  No automatic data type
+conversion is performed.
+\end{funcdesc}
+
+\begin{funcdesc}{writer}{csvfile\optional{,
+                         dialect=\code{'excel'}\optional{, fmtparam}}}
+Return a writer object responsible for converting the user's data into
+delimited strings on the given file-like object.  An optional
+{}\var{dialect} parameter can be given which is used to define a set of
+parameters specific to a particular CSV dialect.  It may be an instance
+of a subclass of the \class{Dialect} class or one of the strings
+returned by the \function{list_dialects} function.  The other optional
+{}\var{fmtparam} keyword arguments can be given to override individual
+formatting parameters in the current dialect.  For more information
+about the dialect and formatting parameters, see
+section~\ref{fmt-params}, ``Dialects and Formatting Parameters'' for
+details of these parameters.  To make it as easy as possible to
+interface with modules which implement the DB API, the value
+\constant{None} is written as the empty string.  While this isn't a
+reversible transformation, it makes it easier to dump SQL NULL data values
+to CSV files without preprocessing the data returned from a
+\code{cursor.fetch*()} call.  All other non-string data are stringified
+with \function{str()} before being written.
+\end{funcdesc}
+
+\begin{funcdesc}{register_dialect}{name, dialect}
+Associate \var{dialect} with \var{name}.  \var{dialect} must be a subclass
+of \class{csv.Dialect}.  \var{name} must be a string or Unicode object.
+\end{funcdesc}
+
+\begin{funcdesc}{unregister_dialect}{name}
+Delete the dialect associated with \var{name} from the dialect registry.  An
+\exception{Error} is raised if \var{name} is not a registered dialect
+name.
+\end{funcdesc}
+
+\begin{funcdesc}{get_dialect}{name}
+Return the dialect associated with \var{name}.  An \exception{Error} is
+raised if \var{name} is not a registered dialect name.
+\end{funcdesc}
+
+\begin{funcdesc}{list_dialects}{}
+Return the names of all registered dialects.
+\end{funcdesc}
+
+
+The \module{csv} module defines the following classes:
+
+\begin{classdesc}{DictReader}{csvfile, fieldnames\optional{,
+                              restkey=\code{None}\optional{,
+			      restval=\code{None}\optional{,
+                              dialect=\code{'excel'}\optional{,
+			      fmtparam}}}}}
+Create an object which operates like a regular reader but maps the
+information read into a dict whose keys are given by the \var{fieldnames}
+parameter.  If the row read has fewer fields than the fieldnames sequence,
+the value of \var{restval} will be used as the default value.  If the row
+read has more fields than the fieldnames sequence, the remaining data is
+added as a sequence keyed by the value of \var{restkey}.  If the row read
+has fewer fields than the fieldnames sequence, the remaining keys take the
+value of the optiona \var{restval} parameter.  All other parameters are
+interpreted as for regular readers.
+\end{classdesc}
+
+
+\begin{classdesc}{DictWriter}{csvfile, fieldnames\optional{,
+                              restval=""\optional{,
+                              extrasaction=\code{'raise'}\optional{,
+                              dialect=\code{'excel'}\optional{, fmtparam}}}}}
+Create an object which operates like a regular writer but maps dictionaries
+onto output rows.  The \var{fieldnames} parameter identifies the order in
+which values in the dictionary passed to the \method{writerow()} method are
+written to the \var{csvfile}.  The optional \var{restval} parameter
+specifies the value to be written if the dictionary is missing a key in
+\var{fieldnames}.  If the dictionary passed to the \method{writerow()}
+method contains a key not found in \var{fieldnames}, the optional
+\var{extrasaction} parameter indicates what action to take.  If it is set
+to \code{'raise'} a \exception{ValueError} is raised.  If it is set to
+\code{'ignore'}, extra values in the dictionary are ignored.  All other
+parameters are interpreted as for regular writers.
+\end{classdesc}
+
+
+\begin{classdesc*}{Dialect}{}
+The \class{Dialect} class is a container class relied on primarily for its
+attributes, which are used to define the parameters for a specific
+\class{reader} or \class{writer} instance.  Dialect objects support the
+following data attributes:
+
+\begin{memberdesc}[string]{delimiter}
+A one-character string used to separate fields.  It defaults to \code{","}.
+\end{memberdesc}
+
+\begin{memberdesc}[boolean]{doublequote}
+Controls how instances of \var{quotechar} appearing inside a field should be
+themselves be quoted.  When \constant{True}, the character is doubledd.
+When \constant{False}, the \var{escapechar} must be a one-character string
+which is used as a prefix to the \var{quotechar}.  It defaults to
+\constant{True}.
+\end{memberdesc}
+
+\begin{memberdesc}{escapechar}
+A one-character string used to escape the \var{delimiter} if \var{quoting}
+is set to \constant{QUOTE_NONE}.  It defaults to \constant{None}.
+\end{memberdesc}
+
+\begin{memberdesc}[string]{lineterminator}
+The string used to terminate lines in the CSV file.  It defaults to
+\code{"\e r\e n"}.
+\end{memberdesc}
+
+\begin{memberdesc}[string]{quotechar}
+A one-character string used to quote elements containing the \var{delimiter}
+or which start with the \var{quotechar}.  It defaults to \code{'"'}.
+\end{memberdesc}
+
+\begin{memberdesc}[integer]{quoting}
+Controls when quotes should be generated by the writer.  It can take on any
+of the \code{QUOTE_*} constants defined below and defaults to
+\constant{QUOTE_MINIMAL}. 
+\end{memberdesc}
+
+\begin{memberdesc}[boolean]{skipinitialspace}
+When \constant{True}, whitespace immediately following the \var{delimiter}
+is ignored.  The default is \constant{False}.
+\end{memberdesc}
+
+\end{classdesc*}
+
+The \module{csv} module defines the following constants:
+
+\begin{datadesc}{QUOTE_ALWAYS}
+Instructs \class{writer} objects to quote all fields.
+\end{datadesc}
+
+\begin{datadesc}{QUOTE_MINIMAL}
+Instructs \class{writer} objects to only quote those fields which contain
+the current \var{delimiter} or begin with the current \var{quotechar}.
+\end{datadesc}
+
+\begin{datadesc}{QUOTE_NONNUMERIC}
+Instructs \class{writer} objects to quote all non-numeric fields.
+\end{datadesc}
+
+\begin{datadesc}{QUOTE_NONE}
+Instructs \class{writer} objects to never quote fields.  When the current
+\var{delimiter} occurs in output data it is preceded by the current
+\var{escapechar} character.  When \constant{QUOTE_NONE} is in effect, it
+is an error not to have a single-character \var{escapechar} defined, even if
+no data to be written contains the \var{delimiter} character.
+\end{datadesc}
+
+
+The \module{csv} module defines the following exception:
+
+\begin{excdesc}{Error}
+Raised by any of the functions when an error is detected.
+\end{excdesc}
+
+
+\subsection{Dialects and Formatting Parameters\label{fmt-params}}
+
+To make it easier to specify the format of input and output records,
+specific formatting parameters are grouped together into dialects.  A
+dialect is a subclass of the \class{Dialect} class having a set of specific
+methods and a single \method{validate()} method.  When creating \class{reader}
+or \class{writer} objects, the programmer can specify a string or a subclass
+of the \class{Dialect} class as the dialect parameter.  In addition to, or
+instead of, the \var{dialect} parameter, the programmer can also specify
+individual formatting parameters, which have the same names as the
+attributes defined above for the \class{Dialect} class.
+
+
+\subsection{Reader Objects}
+
+\class{DictReader} and \var{reader} objects have the following public
+methods:
+
+\begin{methoddesc}{next}{}
+Return the next row of the reader's iterable object as a list, parsed
+according to the current dialect.
+\end{methoddesc}
+
+
+\subsection{Writer Objects}
+
+\class{DictWriter} and \var{writer} objects have the following public
+methods:
+
+\begin{methoddesc}{writerow}{row}
+Write the \var{row} parameter to the writer's file object, formatted
+according to the current dialect.
+\end{methoddesc}
+
+\begin{methoddesc}{writerows}{rows}
+Write all the \var{rows} parameters to the writer's file object, formatted
+according to the current dialect.
+\end{methoddesc}
+
+
+\subsection{Examples}
+
+The ``Hello, world'' of csv reading is
+
+\begin{verbatim}
+    reader = csv.reader(file("some.csv"))
+    for row in reader:
+        print row
+\end{verbatim}
+
+The corresponding simplest possible writing example is
+
+\begin{verbatim}
+    writer = csv.writer(file("some.csv", "w"))
+    for row in someiterable:
+        writer.writerow(row)
+\end{verbatim}
diff --git a/Lib/csv/__init__.py b/Lib/csv/__init__.py
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/Lib/csv/__init__.py
@@ -0,0 +1 @@
+
diff --git a/Lib/csv/csv.py b/Lib/csv/csv.py
new file mode 100644
index 0000000..a3ea4e2
--- /dev/null
+++ b/Lib/csv/csv.py
@@ -0,0 +1,138 @@
+from _csv import Error, __version__, writer, reader, register_dialect, \
+                 unregister_dialect, get_dialect, list_dialects, \
+                 QUOTE_MINIMAL, QUOTE_ALL, QUOTE_NONNUMERIC, QUOTE_NONE, \
+                 __doc__
+
+__all__ = [ "QUOTE_MINIMAL", "QUOTE_ALL", "QUOTE_NONNUMERIC", "QUOTE_NONE",
+            "Error", "Dialect", "excel", "excel_tab", "reader", "writer",
+            "register_dialect", "get_dialect", "list_dialects",
+            "unregister_dialect", "__version__", "DictReader", "DictWriter" ]
+
+class Dialect:
+    _name = ""
+    _valid = False
+    # placeholders
+    delimiter = None
+    quotechar = None
+    escapechar = None
+    doublequote = None
+    skipinitialspace = None
+    lineterminator = None
+    quoting = None
+
+    def __init__(self):
+        if self.__class__ != Dialect:
+            self._valid = True
+        errors = self._validate()
+        if errors != []:
+            raise Error, "Dialect did not validate: %s" % ", ".join(errors)
+
+    def _validate(self):
+        errors = []
+        if not self._valid:
+            errors.append("can't directly instantiate Dialect class")
+
+        if self.delimiter is None:
+            errors.append("delimiter character not set")
+        elif (not isinstance(self.delimiter, str) or
+              len(self.delimiter) > 1):
+            errors.append("delimiter must be one-character string")
+
+        if self.quotechar is None:
+            if self.quoting != QUOTE_NONE:
+                errors.append("quotechar not set")
+        elif (not isinstance(self.quotechar, str) or
+              len(self.quotechar) > 1):
+            errors.append("quotechar must be one-character string")
+
+        if self.lineterminator is None:
+            errors.append("lineterminator not set")
+        elif not isinstance(self.lineterminator, str):
+            errors.append("lineterminator must be a string")
+
+        if self.doublequote not in (True, False):
+            errors.append("doublequote parameter must be True or False")
+
+        if self.skipinitialspace not in (True, False):
+            errors.append("skipinitialspace parameter must be True or False")
+
+        if self.quoting is None:
+            errors.append("quoting parameter not set")
+
+        if self.quoting is QUOTE_NONE:
+            if (not isinstance(self.escapechar, (unicode, str)) or
+                len(self.escapechar) > 1):
+                errors.append("escapechar must be a one-character string or unicode object")
+
+        return errors
+
+class excel(Dialect):
+    delimiter = ','
+    quotechar = '"'
+    doublequote = True
+    skipinitialspace = False
+    lineterminator = '\r\n'
+    quoting = QUOTE_MINIMAL
+register_dialect("excel", excel)
+
+class excel_tab(excel):
+    delimiter = '\t'
+register_dialect("excel-tab", excel_tab)
+
+
+class DictReader:
+    def __init__(self, f, fieldnames, restkey=None, restval=None,
+                 dialect="excel", *args):
+        self.fieldnames = fieldnames    # list of keys for the dict
+        self.restkey = restkey          # key to catch long rows
+        self.restval = restval          # default value for short rows
+        self.reader = reader(f, dialect, *args)
+
+    def __iter__(self):
+        return self
+
+    def next(self):
+        row = self.reader.next()
+        # unlike the basic reader, we prefer not to return blanks,
+        # because we will typically wind up with a dict full of None
+        # values
+        while row == []:
+            row = self.reader.next()
+        d = dict(zip(self.fieldnames, row))
+        lf = len(self.fieldnames)
+        lr = len(row)
+        if lf < lr:
+            d[self.restkey] = row[lf:]
+        elif lf > lr:
+            for key in self.fieldnames[lr:]:
+                d[key] = self.restval
+        return d
+
+
+class DictWriter:
+    def __init__(self, f, fieldnames, restval="", extrasaction="raise",
+                 dialect="excel", *args):
+        self.fieldnames = fieldnames    # list of keys for the dict
+        self.restval = restval          # for writing short dicts
+        if extrasaction.lower() not in ("raise", "ignore"):
+            raise ValueError, \
+                  ("extrasaction (%s) must be 'raise' or 'ignore'" % 
+                   extrasaction)
+        self.extrasaction = extrasaction
+        self.writer = writer(f, dialect, *args)
+
+    def _dict_to_list(self, rowdict):
+        if self.extrasaction == "raise":
+            for k in rowdict.keys():
+                if k not in self.fieldnames:
+                    raise ValueError, "dict contains fields not in fieldnames"
+        return [rowdict.get(key, self.restval) for key in self.fieldnames] 
+
+    def writerow(self, rowdict):
+        return self.writer.writerow(self._dict_to_list(rowdict))
+
+    def writerows(self, rowdicts):
+        rows = []
+        for rowdict in rowdicts:
+            rows.append(self._dict_to_list(rowdict))
+        return self.writer.writerows(rows)
diff --git a/Lib/test/test_csv.py b/Lib/test/test_csv.py
new file mode 100644
index 0000000..64456db
--- /dev/null
+++ b/Lib/test/test_csv.py
@@ -0,0 +1,619 @@
+# Copyright (C) 2001,2002 Python Software Foundation
+# csv package unit tests
+
+import sys
+import unittest
+from StringIO import StringIO
+from csv import csv
+import gc
+
+class Test_Csv(unittest.TestCase):
+    """
+    Test the underlying C csv parser in ways that are not appropriate 
+    from the high level interface. Further tests of this nature are done
+    in TestDialectRegistry.
+    """
+    def test_reader_arg_valid(self):
+        self.assertRaises(TypeError, csv.reader)
+        self.assertRaises(TypeError, csv.reader, None)
+        self.assertRaises(AttributeError, csv.reader, [], bad_attr = 0)
+        self.assertRaises(csv.Error, csv.reader, [], 'foo')
+        class BadClass:
+            def __init__(self):
+                raise IOError
+        self.assertRaises(IOError, csv.reader, [], BadClass)
+        self.assertRaises(TypeError, csv.reader, [], None)
+        class BadDialect:
+            bad_attr = 0
+        self.assertRaises(AttributeError, csv.reader, [], BadDialect)
+
+    def test_writer_arg_valid(self):
+        self.assertRaises(TypeError, csv.writer)
+        self.assertRaises(TypeError, csv.writer, None)
+        self.assertRaises(AttributeError, csv.writer, StringIO(), bad_attr = 0)
+
+    def _test_attrs(self, obj):
+        self.assertEqual(obj.dialect.delimiter, ',')
+        obj.dialect.delimiter = '\t'
+        self.assertEqual(obj.dialect.delimiter, '\t')
+        self.assertRaises(TypeError, delattr, obj.dialect, 'delimiter')
+        self.assertRaises(TypeError, setattr, obj.dialect, 
+                          'lineterminator', None)
+        obj.dialect.escapechar = None
+        self.assertEqual(obj.dialect.escapechar, None)
+        self.assertRaises(TypeError, delattr, obj.dialect, 'quoting')
+        self.assertRaises(TypeError, setattr, obj.dialect, 'quoting', None)
+        obj.dialect.quoting = csv.QUOTE_MINIMAL
+        self.assertEqual(obj.dialect.quoting, csv.QUOTE_MINIMAL)
+
+    def test_reader_attrs(self):
+        self._test_attrs(csv.reader([]))
+
+    def test_writer_attrs(self):
+        self._test_attrs(csv.writer(StringIO()))
+
+    def _write_test(self, fields, expect, **kwargs):
+        fileobj = StringIO()
+        writer = csv.writer(fileobj, **kwargs)
+        writer.writerow(fields)
+        self.assertEqual(fileobj.getvalue(), 
+                         expect + writer.dialect.lineterminator)
+
+    def test_write_arg_valid(self):
+        self.assertRaises(csv.Error, self._write_test, None, '')
+        self._write_test((), '')
+        self._write_test([None], '""')
+        self.assertRaises(csv.Error, self._write_test, 
+                          [None], None, quoting = csv.QUOTE_NONE)
+        # Check that exceptions are passed up the chain
+        class BadList:
+            def __len__(self):
+                return 10;
+            def __getitem__(self, i):
+                if i > 2:
+                    raise IOError
+        self.assertRaises(IOError, self._write_test, BadList(), '')
+        class BadItem:
+            def __str__(self):
+                raise IOError
+        self.assertRaises(IOError, self._write_test, [BadItem()], '')
+
+    def test_write_bigfield(self):
+        # This exercises the buffer realloc functionality
+        bigstring = 'X' * 50000
+        self._write_test([bigstring,bigstring], '%s,%s' % \
+                         (bigstring, bigstring))
+
+    def test_write_quoting(self):
+        self._write_test(['a','1','p,q'], 'a,1,"p,q"')
+        self.assertRaises(csv.Error, 
+                          self._write_test,
+                          ['a','1','p,q'], 'a,1,"p,q"',
+                          quoting = csv.QUOTE_NONE)
+        self._write_test(['a','1','p,q'], 'a,1,"p,q"',
+                         quoting = csv.QUOTE_MINIMAL)
+        self._write_test(['a','1','p,q'], '"a",1,"p,q"',
+                         quoting = csv.QUOTE_NONNUMERIC)
+        self._write_test(['a','1','p,q'], '"a","1","p,q"',
+                         quoting = csv.QUOTE_ALL)
+
+    def test_write_escape(self):
+        self._write_test(['a','1','p,q'], 'a,1,"p,q"',
+                         escapechar='\\')
+# FAILED - needs to be fixed [am]:
+#        self._write_test(['a','1','p,"q"'], 'a,1,"p,\\"q\\"',
+#                         escapechar='\\', doublequote = 0)
+        self._write_test(['a','1','p,q'], 'a,1,p\\,q',
+                         escapechar='\\', quoting = csv.QUOTE_NONE)
+
+    def test_writerows(self):
+        class BrokenFile:
+            def write(self, buf):
+                raise IOError
+        writer = csv.writer(BrokenFile())
+        self.assertRaises(IOError, writer.writerows, [['a']])
+        fileobj = StringIO()
+        writer = csv.writer(fileobj)
+        self.assertRaises(TypeError, writer.writerows, None)
+        writer.writerows([['a','b'],['c','d']])
+        self.assertEqual(fileobj.getvalue(), "a,b\r\nc,d\r\n")
+
+    def _read_test(self, input, expect, **kwargs):
+        reader = csv.reader(input, **kwargs)
+        result = list(reader)
+        self.assertEqual(result, expect)
+
+    def test_read_oddinputs(self):
+        self._read_test([], [])
+        self._read_test([''], [[]])
+        self.assertRaises(csv.Error, self._read_test,
+                          ['"ab"c'], None, strict = 1)
+        # cannot handle null bytes for the moment
+        self.assertRaises(csv.Error, self._read_test,
+                          ['ab\0c'], None, strict = 1)
+        self._read_test(['"ab"c'], [['abc']], doublequote = 0)
+
+    def test_read_eol(self):
+        self._read_test(['a,b'], [['a','b']])
+        self._read_test(['a,b\n'], [['a','b']])
+        self._read_test(['a,b\r\n'], [['a','b']])
+        self._read_test(['a,b\r'], [['a','b']])
+        self.assertRaises(csv.Error, self._read_test, ['a,b\rc,d'], [])
+        self.assertRaises(csv.Error, self._read_test, ['a,b\nc,d'], [])
+        self.assertRaises(csv.Error, self._read_test, ['a,b\r\nc,d'], [])
+
+    def test_read_escape(self):
+        self._read_test(['a,\\b,c'], [['a', '\\b', 'c']], escapechar='\\')
+        self._read_test(['a,b\\,c'], [['a', 'b,c']], escapechar='\\')
+        self._read_test(['a,"b\\,c"'], [['a', 'b,c']], escapechar='\\')
+        self._read_test(['a,"b,\\c"'], [['a', 'b,\\c']], escapechar='\\')
+        self._read_test(['a,"b,c\\""'], [['a', 'b,c"']], escapechar='\\')
+        self._read_test(['a,"b,c"\\'], [['a', 'b,c\\']], escapechar='\\')
+
+    def test_read_bigfield(self):
+        # This exercises the buffer realloc functionality
+        bigstring = 'X' * 50000
+        bigline = '%s,%s' % (bigstring, bigstring)
+        self._read_test([bigline], [[bigstring, bigstring]])
+
+class TestDialectRegistry(unittest.TestCase):
+    def test_registry_badargs(self):
+        self.assertRaises(TypeError, csv.list_dialects, None)
+        self.assertRaises(TypeError, csv.get_dialect)
+        self.assertRaises(csv.Error, csv.get_dialect, None)
+        self.assertRaises(csv.Error, csv.get_dialect, "nonesuch")
+        self.assertRaises(TypeError, csv.unregister_dialect)
+        self.assertRaises(csv.Error, csv.unregister_dialect, None)
+        self.assertRaises(csv.Error, csv.unregister_dialect, "nonesuch")
+        self.assertRaises(TypeError, csv.register_dialect, None)
+        self.assertRaises(TypeError, csv.register_dialect, None, None)
+        self.assertRaises(TypeError, csv.register_dialect, "nonesuch", None)
+        class bogus:
+            def __init__(self):
+                raise KeyError
+        self.assertRaises(KeyError, csv.register_dialect, "nonesuch", bogus)
+
+    def test_registry(self):
+        class myexceltsv(csv.excel):
+            delimiter = "\t"
+        name = "myexceltsv"
+        expected_dialects = csv.list_dialects() + [name]
+        expected_dialects.sort()
+        csv.register_dialect(name, myexceltsv)
+        try:
+            self.failUnless(isinstance(csv.get_dialect(name), myexceltsv))
+            got_dialects = csv.list_dialects()
+            got_dialects.sort()
+            self.assertEqual(expected_dialects, got_dialects)
+        finally:
+            csv.unregister_dialect(name)
+
+    def test_incomplete_dialect(self):
+        class myexceltsv(csv.Dialect):
+            delimiter = "\t"
+        self.assertRaises(csv.Error, myexceltsv)
+
+    def test_space_dialect(self):
+        class space(csv.excel):
+            delimiter = " "
+            quoting = csv.QUOTE_NONE
+            escapechar = "\\"
+
+        s = StringIO("abc def\nc1ccccc1 benzene\n")
+        rdr = csv.reader(s, dialect=space())
+        self.assertEqual(rdr.next(), ["abc", "def"])
+        self.assertEqual(rdr.next(), ["c1ccccc1", "benzene"])
+
+    def test_dialect_apply(self):
+        class testA(csv.excel):
+            delimiter = "\t"
+        class testB(csv.excel):
+            delimiter = ":"
+        class testC(csv.excel):
+            delimiter = "|"
+
+        csv.register_dialect('testC', testC)
+        try:
+            fileobj = StringIO()
+            writer = csv.writer(fileobj)
+            writer.writerow([1,2,3])
+            self.assertEqual(fileobj.getvalue(), "1,2,3\r\n")
+
+            fileobj = StringIO()
+            writer = csv.writer(fileobj, testA)
+            writer.writerow([1,2,3])
+            self.assertEqual(fileobj.getvalue(), "1\t2\t3\r\n")
+
+            fileobj = StringIO()
+            writer = csv.writer(fileobj, dialect=testB())
+            writer.writerow([1,2,3])
+            self.assertEqual(fileobj.getvalue(), "1:2:3\r\n")
+
+            fileobj = StringIO()
+            writer = csv.writer(fileobj, dialect='testC')
+            writer.writerow([1,2,3])
+            self.assertEqual(fileobj.getvalue(), "1|2|3\r\n")
+
+            fileobj = StringIO()
+            writer = csv.writer(fileobj, dialect=testA, delimiter=';')
+            writer.writerow([1,2,3])
+            self.assertEqual(fileobj.getvalue(), "1;2;3\r\n")
+        finally:
+            csv.unregister_dialect('testC')
+
+    def test_bad_dialect(self):
+        # Unknown parameter
+        self.assertRaises(AttributeError, csv.reader, [], bad_attr = 0)
+        # Bad values
+        self.assertRaises(TypeError, csv.reader, [], delimiter = None)
+        self.assertRaises(TypeError, csv.reader, [], quoting = -1)
+        self.assertRaises(TypeError, csv.reader, [], quoting = 100)
+
+class TestCsvBase(unittest.TestCase):
+    def readerAssertEqual(self, input, expected_result):
+        reader = csv.reader(StringIO(input), dialect = self.dialect)
+        fields = list(reader)
+        self.assertEqual(fields, expected_result)
+
+    def writerAssertEqual(self, input, expected_result):
+        fileobj = StringIO()
+        writer = csv.writer(fileobj, dialect = self.dialect)
+        writer.writerows(input)
+        self.assertEqual(fileobj.getvalue(), expected_result)
+
+class TestDialectExcel(TestCsvBase):
+    dialect = 'excel'
+
+    def test_single(self):
+        self.readerAssertEqual('abc', [['abc']])
+
+    def test_simple(self):
+        self.readerAssertEqual('1,2,3,4,5', [['1','2','3','4','5']])
+
+    def test_blankline(self):
+        self.readerAssertEqual('', [])
+
+    def test_empty_fields(self):
+        self.readerAssertEqual(',', [['', '']])
+
+    def test_singlequoted(self):
+        self.readerAssertEqual('""', [['']])
+
+    def test_singlequoted_left_empty(self):
+        self.readerAssertEqual('"",', [['','']])
+
+    def test_singlequoted_right_empty(self):
+        self.readerAssertEqual(',""', [['','']])
+
+    def test_single_quoted_quote(self):
+        self.readerAssertEqual('""""', [['"']])
+
+    def test_quoted_quotes(self):
+        self.readerAssertEqual('""""""', [['""']])
+
+    def test_inline_quote(self):
+        self.readerAssertEqual('a""b', [['a""b']])
+
+    def test_inline_quotes(self):
+        self.readerAssertEqual('a"b"c', [['a"b"c']])
+
+    def test_quotes_and_more(self):
+        self.readerAssertEqual('"a"b', [['ab']])
+
+    def test_lone_quote(self):
+        self.readerAssertEqual('a"b', [['a"b']])
+
+    def test_quote_and_quote(self):
+        self.readerAssertEqual('"a" "b"', [['a "b"']])
+
+    def test_space_and_quote(self):
+        self.readerAssertEqual(' "a"', [[' "a"']])
+
+    def test_quoted(self):
+        self.readerAssertEqual('1,2,3,"I think, therefore I am",5,6', 
+                               [['1', '2', '3', 
+                                 'I think, therefore I am', 
+                                 '5', '6']])
+
+    def test_quoted_quote(self):
+        self.readerAssertEqual('1,2,3,"""I see,"" said the blind man","as he picked up his hammer and saw"',
+                               [['1', '2', '3', 
+                                 '"I see," said the blind man', 
+                                 'as he picked up his hammer and saw']])
+
+    def test_quoted_nl(self):
+        input = '''\
+1,2,3,"""I see,""
+said the blind man","as he picked up his
+hammer and saw"
+9,8,7,6'''
+        self.readerAssertEqual(input,
+                               [['1', '2', '3', 
+                                   '"I see,"\nsaid the blind man', 
+                                   'as he picked up his\nhammer and saw'],
+                                ['9','8','7','6']])
+
+    def test_dubious_quote(self):
+        self.readerAssertEqual('12,12,1",', [['12', '12', '1"', '']])
+
+    def test_null(self):
+        self.writerAssertEqual([], '')
+
+    def test_single(self):
+        self.writerAssertEqual([['abc']], 'abc\r\n')
+
+    def test_simple(self):
+        self.writerAssertEqual([[1, 2, 'abc', 3, 4]], '1,2,abc,3,4\r\n')
+
+    def test_quotes(self):
+        self.writerAssertEqual([[1, 2, 'a"bc"', 3, 4]], '1,2,"a""bc""",3,4\r\n')
+
+    def test_quote_fieldsep(self):
+        self.writerAssertEqual([['abc,def']], '"abc,def"\r\n')
+
+    def test_newlines(self):
+        self.writerAssertEqual([[1, 2, 'a\nbc', 3, 4]], '1,2,"a\nbc",3,4\r\n')
+
+class EscapedExcel(csv.excel):
+    quoting = csv.QUOTE_NONE
+    escapechar = '\\'
+
+class TestEscapedExcel(TestCsvBase):
+    dialect = EscapedExcel()
+
+    def test_escape_fieldsep(self):
+        self.writerAssertEqual([['abc,def']], 'abc\\,def\r\n')
+
+    def test_read_escape_fieldsep(self):
+        self.readerAssertEqual('abc\\,def\r\n', [['abc,def']])
+
+class QuotedEscapedExcel(csv.excel):
+    quoting = csv.QUOTE_NONNUMERIC
+    escapechar = '\\'
+
+class TestQuotedEscapedExcel(TestCsvBase):
+    dialect = QuotedEscapedExcel()
+
+    def test_write_escape_fieldsep(self):
+        self.writerAssertEqual([['abc,def']], '"abc,def"\r\n')
+
+    def test_read_escape_fieldsep(self):
+        self.readerAssertEqual('"abc\\,def"\r\n', [['abc,def']])
+
+# Disabled, pending support in csv.utils module
+class TestDictFields(unittest.TestCase):
+    ### "long" means the row is longer than the number of fieldnames
+    ### "short" means there are fewer elements in the row than fieldnames
+    def test_write_simple_dict(self):
+        fileobj = StringIO()
+        writer = csv.DictWriter(fileobj, fieldnames = ["f1", "f2", "f3"])
+        writer.writerow({"f1": 10, "f3": "abc"})
+        self.assertEqual(fileobj.getvalue(), "10,,abc\r\n")
+
+    def test_write_no_fields(self):
+        fileobj = StringIO()
+        self.assertRaises(TypeError, csv.DictWriter, fileobj)
+
+    def test_read_dict_fields(self):
+        reader = csv.DictReader(StringIO("1,2,abc\r\n"),
+                                fieldnames=["f1", "f2", "f3"])
+        self.assertEqual(reader.next(), {"f1": '1', "f2": '2', "f3": 'abc'})
+
+    def test_read_long(self):
+        reader = csv.DictReader(StringIO("1,2,abc,4,5,6\r\n"),
+                                fieldnames=["f1", "f2"])
+        self.assertEqual(reader.next(), {"f1": '1', "f2": '2',
+                                         None: ["abc", "4", "5", "6"]})
+
+    def test_read_long_with_rest(self):
+        reader = csv.DictReader(StringIO("1,2,abc,4,5,6\r\n"),
+                                fieldnames=["f1", "f2"], restkey="_rest")
+        self.assertEqual(reader.next(), {"f1": '1', "f2": '2',
+                                         "_rest": ["abc", "4", "5", "6"]})
+
+    def test_read_short(self):
+        reader = csv.DictReader(["1,2,abc,4,5,6\r\n","1,2,abc\r\n"],
+                                fieldnames="1 2 3 4 5 6".split(),
+                                restval="DEFAULT")
+        self.assertEqual(reader.next(), {"1": '1', "2": '2', "3": 'abc',
+                                         "4": '4', "5": '5', "6": '6'})
+        self.assertEqual(reader.next(), {"1": '1', "2": '2', "3": 'abc',
+                                         "4": 'DEFAULT', "5": 'DEFAULT',
+                                         "6": 'DEFAULT'})
+
+    def test_read_with_blanks(self):
+        reader = csv.DictReader(["1,2,abc,4,5,6\r\n","\r\n",
+                                 "1,2,abc,4,5,6\r\n"],
+                                fieldnames="1 2 3 4 5 6".split())
+        self.assertEqual(reader.next(), {"1": '1', "2": '2', "3": 'abc',
+                                         "4": '4', "5": '5', "6": '6'})
+        self.assertEqual(reader.next(), {"1": '1', "2": '2', "3": 'abc',
+                                         "4": '4', "5": '5', "6": '6'})
+
+class TestArrayWrites(unittest.TestCase):
+    def test_int_write(self):
+        import array
+        contents = [(20-i) for i in range(20)]
+        a = array.array('i', contents)
+        fileobj = StringIO()
+        writer = csv.writer(fileobj, dialect="excel")
+        writer.writerow(a)
+        expected = ",".join([str(i) for i in a])+"\r\n"
+        self.assertEqual(fileobj.getvalue(), expected)
+
+    def test_double_write(self):
+        import array
+        contents = [(20-i)*0.1 for i in range(20)]
+        a = array.array('d', contents)
+        fileobj = StringIO()
+        writer = csv.writer(fileobj, dialect="excel")
+        writer.writerow(a)
+        expected = ",".join([str(i) for i in a])+"\r\n"
+        self.assertEqual(fileobj.getvalue(), expected)
+
+    def test_float_write(self):
+        import array
+        contents = [(20-i)*0.1 for i in range(20)]
+        a = array.array('f', contents)
+        fileobj = StringIO()
+        writer = csv.writer(fileobj, dialect="excel")
+        writer.writerow(a)
+        expected = ",".join([str(i) for i in a])+"\r\n"
+        self.assertEqual(fileobj.getvalue(), expected)
+
+    def test_char_write(self):
+        import array, string
+        a = array.array('c', string.letters)
+        fileobj = StringIO()
+        writer = csv.writer(fileobj, dialect="excel")
+        writer.writerow(a)
+        expected = ",".join(a)+"\r\n"
+        self.assertEqual(fileobj.getvalue(), expected)
+
+class TestDialectValidity(unittest.TestCase):
+    def test_quoting(self):
+        class mydialect(csv.Dialect):
+            delimiter = ";"
+            escapechar = '\\'
+            doublequote = False
+            skipinitialspace = True
+            lineterminator = '\r\n'
+            quoting = csv.QUOTE_NONE
+        d = mydialect()
+
+        mydialect.quoting = None
+        self.assertRaises(csv.Error, mydialect)
+
+        mydialect.quoting = csv.QUOTE_NONE
+        mydialect.escapechar = None
+        self.assertRaises(csv.Error, mydialect)
+
+        mydialect.doublequote = True
+        mydialect.quoting = csv.QUOTE_ALL
+        mydialect.quotechar = '"'
+        d = mydialect()
+
+        mydialect.quotechar = "''"
+        self.assertRaises(csv.Error, mydialect)
+
+        mydialect.quotechar = 4
+        self.assertRaises(csv.Error, mydialect)
+
+    def test_delimiter(self):
+        class mydialect(csv.Dialect):
+            delimiter = ";"
+            escapechar = '\\'
+            doublequote = False
+            skipinitialspace = True
+            lineterminator = '\r\n'
+            quoting = csv.QUOTE_NONE
+        d = mydialect()
+
+        mydialect.delimiter = ":::"
+        self.assertRaises(csv.Error, mydialect)
+
+        mydialect.delimiter = 4
+        self.assertRaises(csv.Error, mydialect)
+
+    def test_lineterminator(self):
+        class mydialect(csv.Dialect):
+            delimiter = ";"
+            escapechar = '\\'
+            doublequote = False
+            skipinitialspace = True
+            lineterminator = '\r\n'
+            quoting = csv.QUOTE_NONE
+        d = mydialect()
+
+        mydialect.lineterminator = ":::"
+        d = mydialect()
+
+        mydialect.lineterminator = 4
+        self.assertRaises(csv.Error, mydialect)
+
+
+if not hasattr(sys, "gettotalrefcount"):
+    print "*** skipping leakage tests ***"
+else:
+    class NUL:
+        def write(s, *args):
+            pass
+        writelines = write
+
+    class TestLeaks(unittest.TestCase):
+        def test_create_read(self):
+            delta = 0
+            lastrc = sys.gettotalrefcount()
+            for i in xrange(20):
+                gc.collect()
+                self.assertEqual(gc.garbage, [])
+                rc = sys.gettotalrefcount()
+                csv.reader(["a,b,c\r\n"])
+                csv.reader(["a,b,c\r\n"])
+                csv.reader(["a,b,c\r\n"])
+                delta = rc-lastrc
+                lastrc = rc
+            # if csv.reader() leaks, last delta should be 3 or more
+            self.assertEqual(delta < 3, True)
+
+        def test_create_write(self):
+            delta = 0
+            lastrc = sys.gettotalrefcount()
+            s = NUL()
+            for i in xrange(20):
+                gc.collect()
+                self.assertEqual(gc.garbage, [])
+                rc = sys.gettotalrefcount()
+                csv.writer(s)
+                csv.writer(s)
+                csv.writer(s)
+                delta = rc-lastrc
+                lastrc = rc
+            # if csv.writer() leaks, last delta should be 3 or more
+            self.assertEqual(delta < 3, True)
+
+        def test_read(self):
+            delta = 0
+            rows = ["a,b,c\r\n"]*5
+            lastrc = sys.gettotalrefcount()
+            for i in xrange(20):
+                gc.collect()
+                self.assertEqual(gc.garbage, [])
+                rc = sys.gettotalrefcount()
+                rdr = csv.reader(rows)
+                for row in rdr:
+                    pass
+                delta = rc-lastrc
+                lastrc = rc
+            # if reader leaks during read, delta should be 5 or more
+            self.assertEqual(delta < 5, True)
+
+        def test_write(self):
+            delta = 0
+            rows = [[1,2,3]]*5
+            s = NUL()
+            lastrc = sys.gettotalrefcount()
+            for i in xrange(20):
+                gc.collect()
+                self.assertEqual(gc.garbage, [])
+                rc = sys.gettotalrefcount()
+                writer = csv.writer(s)
+                for row in rows:
+                    writer.writerow(row)
+                delta = rc-lastrc
+                lastrc = rc
+            # if writer leaks during write, last delta should be 5 or more
+            self.assertEqual(delta < 5, True)
+
+def _testclasses():
+    mod = sys.modules[__name__]
+    return [getattr(mod, name) for name in dir(mod) if name.startswith('Test')]
+
+def suite():
+    suite = unittest.TestSuite()
+    for testclass in _testclasses():
+        suite.addTest(unittest.makeSuite(testclass))
+    return suite
+
+if __name__ == '__main__':
+    unittest.main(defaultTest='suite')
diff --git a/Modules/_csv.c b/Modules/_csv.c
new file mode 100644
index 0000000..701904a
--- /dev/null
+++ b/Modules/_csv.c
@@ -0,0 +1,1465 @@
+/* TODO:
+*/
+
+#include "Python.h"
+#include "structmember.h"
+
+/* begin 2.2 compatibility macros */
+#ifndef PyDoc_STRVAR
+/* Define macros for inline documentation. */
+#define PyDoc_VAR(name) static char name[]
+#define PyDoc_STRVAR(name,str) PyDoc_VAR(name) = PyDoc_STR(str)
+#ifdef WITH_DOC_STRINGS
+#define PyDoc_STR(str) str
+#else
+#define PyDoc_STR(str) ""
+#endif
+#endif /* ifndef PyDoc_STRVAR */
+
+#ifndef PyMODINIT_FUNC
+#	if defined(__cplusplus)
+#		define PyMODINIT_FUNC extern "C" void
+#	else /* __cplusplus */
+#		define PyMODINIT_FUNC void
+#	endif /* __cplusplus */
+#endif
+/* end 2.2 compatibility macros */
+
+static PyObject *error_obj;	/* CSV exception */
+static PyObject *dialects;      /* Dialect registry */
+
+typedef enum {
+	START_RECORD, START_FIELD, ESCAPED_CHAR, IN_FIELD, 
+	IN_QUOTED_FIELD, ESCAPE_IN_QUOTED_FIELD, QUOTE_IN_QUOTED_FIELD
+} ParserState;
+
+typedef enum {
+	QUOTE_MINIMAL, QUOTE_ALL, QUOTE_NONNUMERIC, QUOTE_NONE
+} QuoteStyle;
+
+typedef struct {
+	QuoteStyle style;
+	char *name;
+} StyleDesc;
+
+static StyleDesc quote_styles[] = {
+	{ QUOTE_MINIMAL,    "QUOTE_MINIMAL" },
+	{ QUOTE_ALL,        "QUOTE_ALL" },
+	{ QUOTE_NONNUMERIC, "QUOTE_NONNUMERIC" },
+	{ QUOTE_NONE,       "QUOTE_NONE" },
+	{ 0 }
+};
+
+typedef struct {
+        PyObject_HEAD
+        
+	int doublequote;	/* is " represented by ""? */
+	char delimiter;		/* field separator */
+	char quotechar;		/* quote character */
+	char escapechar;	/* escape character */
+	int skipinitialspace;	/* ignore spaces following delimiter? */
+	PyObject *lineterminator; /* string to write between records */
+	QuoteStyle quoting;	/* style of quoting to write */
+
+	int strict;		/* raise exception on bad CSV */
+} DialectObj;
+
+staticforward PyTypeObject Dialect_Type;
+
+typedef struct {
+        PyObject_HEAD
+
+        PyObject *input_iter;   /* iterate over this for input lines */
+
+        DialectObj *dialect;    /* parsing dialect */
+
+	PyObject *fields;	/* field list for current record */
+	ParserState state;	/* current CSV parse state */
+	char *field;		/* build current field in here */
+	int field_size;		/* size of allocated buffer */
+	int field_len;		/* length of current field */
+	int had_parse_error;	/* did we have a parse error? */
+} ReaderObj;
+
+staticforward PyTypeObject Reader_Type;
+
+#define ReaderObject_Check(v)   ((v)->ob_type == &Reader_Type)
+
+typedef struct {
+        PyObject_HEAD
+
+        PyObject *writeline;    /* write output lines to this file */
+
+        DialectObj *dialect;    /* parsing dialect */
+
+	char *rec;		/* buffer for parser.join */
+	int rec_size;		/* size of allocated record */
+	int rec_len;		/* length of record */
+	int num_fields;		/* number of fields in record */
+} WriterObj;        
+
+staticforward PyTypeObject Writer_Type;
+
+/*
+ * DIALECT class
+ */
+
+static PyObject *
+get_dialect_from_registry(PyObject * name_obj)
+{
+        PyObject *dialect_obj;
+
+        dialect_obj = PyDict_GetItem(dialects, name_obj);
+        if (dialect_obj == NULL)
+            return PyErr_Format(error_obj, "unknown dialect");
+        Py_INCREF(dialect_obj);
+        return dialect_obj;
+}
+
+static int
+check_delattr(PyObject *v)
+{
+	if (v == NULL) {
+		PyErr_SetString(PyExc_TypeError, 
+                                "Cannot delete attribute");
+		return -1;
+        }
+        return 0;
+}
+
+static PyObject *
+get_string(PyObject *str)
+{
+        Py_XINCREF(str);
+        return str;
+}
+
+static int
+set_string(PyObject **str, PyObject *v)
+{
+        if (check_delattr(v) < 0)
+                return -1;
+        if (!PyString_Check(v) && !PyUnicode_Check(v)) {
+                PyErr_BadArgument();
+                return -1;
+        }
+        Py_XDECREF(*str);
+        Py_INCREF(v);
+        *str = v;
+        return 0;
+}
+
+static PyObject *
+get_nullchar_as_None(char c)
+{
+        if (c == '\0') {
+                Py_INCREF(Py_None);
+                return Py_None;
+        }
+        else
+                return PyString_FromStringAndSize((char*)&c, 1);
+}
+
+static int
+set_None_as_nullchar(char * addr, PyObject *v)
+{
+        if (check_delattr(v) < 0)
+                return -1;
+        if (v == Py_None)
+                *addr = '\0';
+        else if (!PyString_Check(v) || PyString_Size(v) != 1) {
+                PyErr_BadArgument();
+                return -1;
+        }
+        else
+             *addr = PyString_AsString(v)[0];
+        return 0;
+}
+
+static PyObject *
+Dialect_get_lineterminator(DialectObj *self)
+{
+        return get_string(self->lineterminator);
+}
+
+static int
+Dialect_set_lineterminator(DialectObj *self, PyObject *value)
+{
+        return set_string(&self->lineterminator, value);
+}
+
+static PyObject *
+Dialect_get_escapechar(DialectObj *self)
+{
+        return get_nullchar_as_None(self->escapechar);
+}
+
+static int
+Dialect_set_escapechar(DialectObj *self, PyObject *value)
+{
+        return set_None_as_nullchar(&self->escapechar, value);
+}
+
+static PyObject *
+Dialect_get_quoting(DialectObj *self)
+{
+        return PyInt_FromLong(self->quoting);
+}
+
+static int
+Dialect_set_quoting(DialectObj *self, PyObject *v)
+{
+        int quoting;
+        StyleDesc *qs = quote_styles;
+
+        if (check_delattr(v) < 0)
+                return -1;
+        if (!PyInt_Check(v)) {
+                PyErr_BadArgument();
+                return -1;
+        }
+        quoting = PyInt_AsLong(v);
+	for (qs = quote_styles; qs->name; qs++) {
+		if (qs->style == quoting) {
+                        self->quoting = quoting;
+                        return 0;
+                }
+        }
+        PyErr_BadArgument();
+        return -1;
+}
+
+static struct PyMethodDef Dialect_methods[] = {
+	{ NULL, NULL }
+};
+
+#define D_OFF(x) offsetof(DialectObj, x)
+
+static struct PyMemberDef Dialect_memberlist[] = {
+	{ "quotechar",          T_CHAR, D_OFF(quotechar) },
+	{ "delimiter",          T_CHAR, D_OFF(delimiter) },
+	{ "skipinitialspace",   T_INT, D_OFF(skipinitialspace) },
+	{ "doublequote",        T_INT, D_OFF(doublequote) },
+	{ "strict",             T_INT, D_OFF(strict) },
+	{ NULL }
+};
+
+static PyGetSetDef Dialect_getsetlist[] = {
+        { "escapechar", (getter)Dialect_get_escapechar, 
+                (setter)Dialect_set_escapechar },
+        { "lineterminator", (getter)Dialect_get_lineterminator, 
+                (setter)Dialect_set_lineterminator },
+        { "quoting", (getter)Dialect_get_quoting, 
+                (setter)Dialect_set_quoting },
+        {NULL},
+};
+
+static void
+Dialect_dealloc(DialectObj *self)
+{
+        Py_XDECREF(self->lineterminator);
+	/*PyMem_DEL(self);*/
+        self->ob_type->tp_free((PyObject *)self);
+}
+
+static int
+dialect_init(DialectObj * self, PyObject * args, PyObject * kwargs)
+{
+        PyObject *dialect = NULL, *name_obj, *value_obj;
+
+	self->quotechar = '"';
+	self->delimiter = ',';
+	self->escapechar = '\0';
+	self->skipinitialspace = 0;
+        Py_XDECREF(self->lineterminator);
+	self->lineterminator = PyString_FromString("\r\n");
+        if (self->lineterminator == NULL)
+                return -1;
+	self->quoting = QUOTE_MINIMAL;
+	self->doublequote = 1;
+	self->strict = 0;
+
+        if (!PyArg_ParseTuple(args, "|O", &dialect))
+                return -1;
+        Py_XINCREF(dialect);
+        if (kwargs != NULL) {
+                PyObject * key = PyString_FromString("dialect");
+                PyObject * d;
+
+                d = PyDict_GetItem(kwargs, key);
+                if (d) {
+                        Py_INCREF(d);
+                        Py_XDECREF(dialect);
+                        PyDict_DelItem(kwargs, key);
+                        dialect = d;
+                }
+                Py_DECREF(key);
+        }
+        if (dialect != NULL) {
+                int i;
+                PyObject * dir_list;
+
+                /* If dialect is a string, look it up in our registry */
+                if (PyString_Check(dialect) || PyUnicode_Check(dialect)) {
+                        PyObject * new_dia;
+                        new_dia = get_dialect_from_registry(dialect);
+                        Py_DECREF(dialect);
+                        if (new_dia == NULL)
+                                return -1;
+                        dialect = new_dia;
+                }
+                /* A class rather than an instance? Instanciate */
+                if (PyObject_TypeCheck(dialect, &PyClass_Type)) {
+                        PyObject * new_dia;
+                        new_dia = PyObject_CallFunction(dialect, "");
+                        Py_DECREF(dialect);
+                        if (new_dia == NULL)
+                                return -1;
+                        dialect = new_dia;
+                }
+                /* Make sure we finally have an instance */
+                if (!PyInstance_Check(dialect) ||
+                    (dir_list = PyObject_Dir(dialect)) == NULL) {
+                        PyErr_SetString(PyExc_TypeError,
+                                        "dialect must be an instance");
+                        Py_DECREF(dialect);
+                        return -1;
+                }
+                /* And extract the attributes */
+                for (i = 0; i < PyList_GET_SIZE(dir_list); ++i) {
+                        name_obj = PyList_GET_ITEM(dir_list, i);
+                        if (PyString_AsString(name_obj)[0] == '_')
+                                continue;
+                        value_obj = PyObject_GetAttr(dialect, name_obj);
+                        if (value_obj) {
+                                if (PyObject_SetAttr((PyObject *)self, 
+                                                     name_obj, value_obj)) {
+                                        Py_DECREF(dir_list);
+                                        return -1;
+                                }
+                                Py_DECREF(value_obj);
+                        }
+                }
+                Py_DECREF(dir_list);
+                Py_DECREF(dialect);
+        }
+        if (kwargs != NULL) {
+                int pos = 0;
+
+                while (PyDict_Next(kwargs, &pos, &name_obj, &value_obj)) {
+                        if (PyObject_SetAttr((PyObject *)self, 
+                                             name_obj, value_obj))
+                                return -1;
+                }
+        }
+        return 0;
+}
+
+static PyObject *
+dialect_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)
+{
+        DialectObj *self;
+        self = (DialectObj *)type->tp_alloc(type, 0);
+        if (self != NULL) {
+                self->lineterminator = NULL;
+        }
+        return (PyObject *)self;
+}
+
+
+PyDoc_STRVAR(Dialect_Type_doc, 
+"CSV dialect\n"
+"\n"
+"The Dialect type records CSV parsing and generation options.\n");
+
+static PyTypeObject Dialect_Type = {
+	PyObject_HEAD_INIT(NULL)
+	0,                                      /* ob_size */
+	"_csv.Dialect",                         /* tp_name */
+	sizeof(DialectObj),                     /* tp_basicsize */
+	0,                                      /* tp_itemsize */
+	/*  methods  */
+	(destructor)Dialect_dealloc,            /* tp_dealloc */
+	(printfunc)0,                           /* tp_print */
+	(getattrfunc)0,                         /* tp_getattr */
+	(setattrfunc)0,                         /* tp_setattr */
+	(cmpfunc)0,                             /* tp_compare */
+	(reprfunc)0,                            /* tp_repr */
+	0,                                      /* tp_as_number */
+	0,                                      /* tp_as_sequence */
+	0,                                      /* tp_as_mapping */
+	(hashfunc)0,                            /* tp_hash */
+	(ternaryfunc)0,                         /* tp_call */
+	(reprfunc)0,                    	/* tp_str */
+	0,                                      /* tp_getattro */
+        0,                                      /* tp_setattro */
+        0,                                      /* tp_as_buffer */
+        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /* tp_flags */
+	Dialect_Type_doc,                       /* tp_doc */
+        0,                                      /* tp_traverse */
+        0,                                      /* tp_clear */
+        0,                                      /* tp_richcompare */
+        0,                                      /* tp_weaklistoffset */
+        0,                                      /* tp_iter */
+        0,                                      /* tp_iternext */
+        Dialect_methods,                        /* tp_methods */
+        Dialect_memberlist,                     /* tp_members */
+        Dialect_getsetlist,                     /* tp_getset */
+	0,					/* tp_base */
+	0,					/* tp_dict */
+	0,					/* tp_descr_get */
+	0,					/* tp_descr_set */
+	0,					/* tp_dictoffset */
+	(initproc)dialect_init,			/* tp_init */
+	PyType_GenericAlloc,	                /* tp_alloc */
+	dialect_new,			        /* tp_new */
+	0,                           /* tp_free */
+};
+
+static void
+parse_save_field(ReaderObj *self)
+{
+	PyObject *field;
+
+	field = PyString_FromStringAndSize(self->field, self->field_len);
+	if (field != NULL) {
+		PyList_Append(self->fields, field);
+		Py_XDECREF(field);
+	}
+	self->field_len = 0;
+}
+
+static int
+parse_grow_buff(ReaderObj *self)
+{
+	if (self->field_size == 0) {
+		self->field_size = 4096;
+		self->field = PyMem_Malloc(self->field_size);
+	}
+	else {
+		self->field_size *= 2;
+		self->field = PyMem_Realloc(self->field, self->field_size);
+	}
+	if (self->field == NULL) {
+		PyErr_NoMemory();
+		return 0;
+	}
+	return 1;
+}
+
+static void
+parse_add_char(ReaderObj *self, char c)
+{
+	if (self->field_len == self->field_size && !parse_grow_buff(self))
+		return;
+	self->field[self->field_len++] = c;
+}
+
+static void
+parse_process_char(ReaderObj *self, char c)
+{
+        DialectObj *dialect = self->dialect;
+
+	switch (self->state) {
+	case START_RECORD:
+		/* start of record */
+		if (c == '\n')
+			/* empty line - return [] */
+			break;
+		/* normal character - handle as START_FIELD */
+		self->state = START_FIELD;
+		/* fallthru */
+	case START_FIELD:
+		/* expecting field */
+		if (c == '\n') {
+			/* save empty field - return [fields] */
+			parse_save_field(self);
+			self->state = START_RECORD;
+		}
+		else if (c == dialect->quotechar) {
+			/* start quoted field */
+			self->state = IN_QUOTED_FIELD;
+		}
+		else if (c == dialect->escapechar) {
+			/* possible escaped character */
+			self->state = ESCAPED_CHAR;
+		}
+		else if (c == ' ' && dialect->skipinitialspace)
+			/* ignore space at start of field */
+			;
+		else if (c == dialect->delimiter) {
+			/* save empty field */
+			parse_save_field(self);
+		}
+		else {
+			/* begin new unquoted field */
+			parse_add_char(self, c);
+			self->state = IN_FIELD;
+		}
+		break;
+
+	case ESCAPED_CHAR:
+		if (c != dialect->escapechar && 
+                    c != dialect->delimiter &&
+		    c != dialect->quotechar)
+			parse_add_char(self, dialect->escapechar);
+		parse_add_char(self, c);
+		self->state = IN_FIELD;
+		break;
+
+	case IN_FIELD:
+		/* in unquoted field */
+		if (c == '\n') {
+			/* end of line - return [fields] */
+			parse_save_field(self);
+			self->state = START_RECORD;
+		}
+		else if (c == dialect->escapechar) {
+			/* possible escaped character */
+			self->state = ESCAPED_CHAR;
+		}
+		else if (c == dialect->delimiter) {
+			/* save field - wait for new field */
+			parse_save_field(self);
+			self->state = START_FIELD;
+		}
+		else {
+			/* normal character - save in field */
+			parse_add_char(self, c);
+		}
+		break;
+
+	case IN_QUOTED_FIELD:
+		/* in quoted field */
+		if (c == '\n') {
+			/* end of line - save '\n' in field */
+			parse_add_char(self, '\n');
+		}
+		else if (c == dialect->escapechar) {
+			/* Possible escape character */
+			self->state = ESCAPE_IN_QUOTED_FIELD;
+		}
+		else if (c == dialect->quotechar) {
+			if (dialect->doublequote) {
+				/* doublequote; " represented by "" */
+				self->state = QUOTE_IN_QUOTED_FIELD;
+			}
+			else {
+				/* end of quote part of field */
+				self->state = IN_FIELD;
+			}
+		}
+		else {
+			/* normal character - save in field */
+			parse_add_char(self, c);
+		}
+		break;
+
+	case ESCAPE_IN_QUOTED_FIELD:
+		if (c != dialect->escapechar && 
+                    c != dialect->delimiter &&
+		    c != dialect->quotechar)
+			parse_add_char(self, dialect->escapechar);
+		parse_add_char(self, c);
+		self->state = IN_QUOTED_FIELD;
+		break;
+
+	case QUOTE_IN_QUOTED_FIELD:
+		/* doublequote - seen a quote in an quoted field */
+		if (dialect->quoting != QUOTE_NONE && 
+                    c == dialect->quotechar) {
+			/* save "" as " */
+			parse_add_char(self, c);
+			self->state = IN_QUOTED_FIELD;
+		}
+		else if (c == dialect->delimiter) {
+			/* save field - wait for new field */
+			parse_save_field(self);
+			self->state = START_FIELD;
+		}
+		else if (c == '\n') {
+			/* end of line - return [fields] */
+			parse_save_field(self);
+			self->state = START_RECORD;
+		}
+		else if (!dialect->strict) {
+			parse_add_char(self, c);
+			self->state = IN_FIELD;
+		}
+		else {
+			/* illegal */
+			self->had_parse_error = 1;
+			PyErr_Format(error_obj, "%c expected after %c", 
+					dialect->delimiter, 
+                                        dialect->quotechar);
+		}
+		break;
+
+	}
+}
+
+/*
+ * READER
+ */
+#define R_OFF(x) offsetof(ReaderObj, x)
+
+static struct PyMemberDef Reader_memberlist[] = {
+	{ "dialect", T_OBJECT, R_OFF(dialect), RO },
+	{ NULL }
+};
+
+static PyObject *
+Reader_getiter(ReaderObj *self)
+{
+	Py_INCREF(self);
+	return (PyObject *)self;
+}
+
+static PyObject *
+Reader_iternext(ReaderObj *self)
+{
+        PyObject *lineobj;
+        PyObject *fields;
+        char *line;
+
+        do {
+                lineobj = PyIter_Next(self->input_iter);
+                if (lineobj == NULL) {
+                        /* End of input OR exception */
+                        if (!PyErr_Occurred() && self->field_len != 0)
+                                return PyErr_Format(error_obj,
+                                                    "newline inside string");
+                        return NULL;
+                }
+
+                if (self->had_parse_error) {
+                        if (self->fields) {
+                                Py_XDECREF(self->fields);
+                        }
+                        self->fields = PyList_New(0);
+                        self->field_len = 0;
+                        self->state = START_RECORD;
+                        self->had_parse_error = 0;
+                }
+                line = PyString_AsString(lineobj);
+
+                if (line == NULL) {
+                        Py_DECREF(lineobj);
+                        return NULL;
+                }
+		if (strlen(line) < PyString_GET_SIZE(lineobj)) {
+			self->had_parse_error = 1;
+			Py_DECREF(lineobj);
+			return PyErr_Format(error_obj,
+					    "string with NUL bytes");
+		}
+
+                /* Process line of text - send '\n' to processing code to
+                represent end of line.  End of line which is not at end of
+                string is an error. */
+                while (*line) {
+                        char c;
+
+                        c = *line++;
+                        if (c == '\r') {
+                                c = *line++;
+                                if (c == '\0')
+                                        /* macintosh end of line */
+                                        break;
+                                if (c == '\n') {
+                                        c = *line++;
+                                        if (c == '\0')
+                                                /* DOS end of line */
+                                                break;
+                                }
+                                self->had_parse_error = 1;
+                                Py_DECREF(lineobj);
+                                return PyErr_Format(error_obj,
+                                                    "newline inside string");
+                        }
+                        if (c == '\n') {
+                                c = *line++;
+                                if (c == '\0')
+                                        /* unix end of line */
+                                        break;
+                                self->had_parse_error = 1;
+                                Py_DECREF(lineobj);
+                                return PyErr_Format(error_obj, 
+                                                    "newline inside string");
+                        }
+                        parse_process_char(self, c);
+                        if (PyErr_Occurred()) {
+                                Py_DECREF(lineobj);
+                                return NULL;
+                        }
+                }
+                parse_process_char(self, '\n');
+                Py_DECREF(lineobj);
+        } while (self->state != START_RECORD);
+
+        fields = self->fields;
+        self->fields = PyList_New(0);
+        return fields;
+}
+
+static void
+Reader_dealloc(ReaderObj *self)
+{
+        Py_XDECREF(self->dialect);
+        Py_XDECREF(self->input_iter);
+        Py_XDECREF(self->fields);
+	PyMem_DEL(self);
+}
+
+PyDoc_STRVAR(Reader_Type_doc,
+"CSV reader\n"
+"\n"
+"Reader objects are responsible for reading and parsing tabular data\n"
+"in CSV format.\n"
+);
+
+static struct PyMethodDef Reader_methods[] = {
+	{ NULL, NULL }
+};
+
+static PyTypeObject Reader_Type = {
+	PyObject_HEAD_INIT(NULL)
+	0,                                      /*ob_size*/
+	"_csv.reader",                          /*tp_name*/
+	sizeof(ReaderObj),                      /*tp_basicsize*/
+	0,                                      /*tp_itemsize*/
+	/* methods */
+	(destructor)Reader_dealloc,             /*tp_dealloc*/
+	(printfunc)0,                           /*tp_print*/
+	(getattrfunc)0,                         /*tp_getattr*/
+	(setattrfunc)0,                         /*tp_setattr*/
+	(cmpfunc)0,                             /*tp_compare*/
+	(reprfunc)0,                            /*tp_repr*/
+	0,                                      /*tp_as_number*/
+	0,                                      /*tp_as_sequence*/
+	0,                                      /*tp_as_mapping*/
+	(hashfunc)0,                            /*tp_hash*/
+	(ternaryfunc)0,                         /*tp_call*/
+	(reprfunc)0,                    	/*tp_str*/
+	0,                                      /*tp_getattro*/
+        0,                                      /*tp_setattro*/
+        0,                                      /*tp_as_buffer*/
+        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+	Reader_Type_doc,                        /*tp_doc*/
+        0,                                      /*tp_traverse*/
+        0,                                      /*tp_clear*/
+        0,                                      /*tp_richcompare*/
+        0,                                      /*tp_weaklistoffset*/
+        (getiterfunc)Reader_getiter,            /*tp_iter*/
+        (getiterfunc)Reader_iternext,           /*tp_iternext*/
+        Reader_methods,                         /*tp_methods*/
+        Reader_memberlist,                      /*tp_members*/
+        0,                                      /*tp_getset*/
+
+};
+
+static PyObject *
+csv_reader(PyObject *module, PyObject *args, PyObject *keyword_args)
+{
+        PyObject * iterator, * dialect = NULL, *ctor_args;
+        ReaderObj * self = PyObject_NEW(ReaderObj, &Reader_Type);
+
+        if (!self)
+                return NULL;
+
+        self->dialect = NULL;
+        self->input_iter = self->fields = NULL;
+
+        self->fields = NULL;
+        self->input_iter = NULL;
+	self->had_parse_error = 0;
+	self->field = NULL;
+	self->field_size = 0;
+	self->field_len = 0;
+	self->state = START_RECORD;
+
+        if (!PyArg_ParseTuple(args, "O|O", &iterator, &dialect)) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->input_iter = PyObject_GetIter(iterator);
+        if (self->input_iter == NULL) {
+                PyErr_SetString(PyExc_TypeError, 
+                                "argument 1 must be an iterator");
+                Py_DECREF(self);
+                return NULL;
+        }
+        ctor_args = Py_BuildValue(dialect ? "(O)" : "()", dialect);
+        if (ctor_args == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->dialect = (DialectObj *)PyObject_Call((PyObject *)&Dialect_Type,
+                                                    ctor_args, keyword_args);
+        Py_DECREF(ctor_args);
+        if (self->dialect == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+	self->fields = PyList_New(0);
+	if (self->fields == NULL) {
+		Py_DECREF(self);
+		return NULL;
+	}
+
+        return (PyObject *)self;
+}
+
+/*
+ * WRITER
+ */
+/* ---------------------------------------------------------------- */
+static void
+join_reset(WriterObj *self)
+{
+	self->rec_len = 0;
+	self->num_fields = 0;
+}
+
+#define MEM_INCR 32768
+
+/* Calculate new record length or append field to record.  Return new
+ * record length.
+ */
+static int
+join_append_data(WriterObj *self, char *field, int quote_empty,
+		 int *quoted, int copy_phase)
+{
+        DialectObj *dialect = self->dialect;
+	int i, rec_len;
+
+	rec_len = self->rec_len;
+
+	/* If this is not the first field we need a field separator.
+	 */
+	if (self->num_fields > 0) {
+		if (copy_phase)
+			self->rec[rec_len] = dialect->delimiter;
+		rec_len++;
+	}
+	/* Handle preceding quote.
+	 */
+	switch (dialect->quoting) {
+	case QUOTE_ALL:
+		*quoted = 1;
+		if (copy_phase)
+			self->rec[rec_len] = dialect->quotechar;
+		rec_len++;
+		break;
+	case QUOTE_MINIMAL:
+	case QUOTE_NONNUMERIC:
+		/* We only know about quoted in the copy phase.
+		 */
+		if (copy_phase && *quoted) {
+			self->rec[rec_len] = dialect->quotechar;
+			rec_len++;
+		}
+		break;
+	case QUOTE_NONE:
+		break;
+	}
+	/* Copy/count field data.
+	 */
+	for (i = 0;; i++) {
+		char c = field[i];
+
+		if (c == '\0')
+			break;
+		/* If in doublequote mode we escape quote chars with a
+		 * quote.
+		 */
+		if (dialect->quoting != QUOTE_NONE && 
+                    c == dialect->quotechar && dialect->doublequote) {
+			if (copy_phase)
+				self->rec[rec_len] = dialect->quotechar;
+			*quoted = 1;
+			rec_len++;
+		}
+
+		/* Some special characters need to be escaped.  If we have a
+		 * quote character switch to quoted field instead of escaping
+		 * individual characters.
+		 */
+		if (!*quoted
+		    && (c == dialect->delimiter || 
+                        c == dialect->escapechar || 
+                        c == '\n' || c == '\r')) {
+			if (dialect->quoting != QUOTE_NONE)
+				*quoted = 1;
+			else if (dialect->escapechar) {
+				if (copy_phase)
+					self->rec[rec_len] = dialect->escapechar;
+				rec_len++;
+			}
+			else {
+				PyErr_Format(error_obj, 
+                                             "delimiter must be quoted or escaped");
+				return -1;
+			}
+		}
+		/* Copy field character into record buffer.
+		 */
+		if (copy_phase)
+			self->rec[rec_len] = c;
+		rec_len++;
+	}
+
+	/* If field is empty check if it needs to be quoted.
+	 */
+	if (i == 0 && quote_empty) {
+		if (dialect->quoting == QUOTE_NONE) {
+			PyErr_Format(error_obj,
+                                     "single empty field record must be quoted");
+			return -1;
+		} else
+			*quoted = 1;
+	}
+
+	/* Handle final quote character on field.
+	 */
+	if (*quoted) {
+		if (copy_phase)
+			self->rec[rec_len] = dialect->quotechar;
+		else
+			/* Didn't know about leading quote until we found it
+			 * necessary in field data - compensate for it now.
+			 */
+			rec_len++;
+		rec_len++;
+	}
+
+	return rec_len;
+}
+
+static int
+join_check_rec_size(WriterObj *self, int rec_len)
+{
+	if (rec_len > self->rec_size) {
+		if (self->rec_size == 0) {
+			self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;
+			self->rec = PyMem_Malloc(self->rec_size);
+		}
+		else {
+			char *old_rec = self->rec;
+
+			self->rec_size = (rec_len / MEM_INCR + 1) * MEM_INCR;
+			self->rec = PyMem_Realloc(self->rec, self->rec_size);
+			if (self->rec == NULL)
+				PyMem_Free(old_rec);
+		}
+		if (self->rec == NULL) {
+			PyErr_NoMemory();
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static int
+join_append(WriterObj *self, char *field, int *quoted, int quote_empty)
+{
+	int rec_len;
+
+	rec_len = join_append_data(self, field, quote_empty, quoted, 0);
+	if (rec_len < 0)
+		return 0;
+
+	/* grow record buffer if necessary */
+	if (!join_check_rec_size(self, rec_len))
+		return 0;
+
+	self->rec_len = join_append_data(self, field, quote_empty, quoted, 1);
+	self->num_fields++;
+
+	return 1;
+}
+
+static int
+join_append_lineterminator(WriterObj *self)
+{
+	int terminator_len;
+
+	terminator_len = PyString_Size(self->dialect->lineterminator);
+
+	/* grow record buffer if necessary */
+	if (!join_check_rec_size(self, self->rec_len + terminator_len))
+		return 0;
+
+	memmove(self->rec + self->rec_len,
+		PyString_AsString(self->dialect->lineterminator), 
+                terminator_len);
+	self->rec_len += terminator_len;
+
+	return 1;
+}
+
+PyDoc_STRVAR(csv_writerow_doc,
+"join(sequence) -> string\n"
+"\n"
+"Construct a CSV record from a sequence of fields.  Non-string\n"
+"elements will be converted to string.");
+
+static PyObject *
+csv_writerow(WriterObj *self, PyObject *seq)
+{
+        DialectObj *dialect = self->dialect;
+	int len, i;
+
+	if (!PySequence_Check(seq))
+		return PyErr_Format(error_obj, "sequence expected");
+
+	len = PySequence_Length(seq);
+	if (len < 0)
+		return NULL;
+
+	/* Join all fields in internal buffer.
+	 */
+	join_reset(self);
+	for (i = 0; i < len; i++) {
+		PyObject *field;
+		int append_ok;
+		int quoted;
+
+		field = PySequence_GetItem(seq, i);
+		if (field == NULL)
+			return NULL;
+
+		quoted = 0;
+		if (dialect->quoting == QUOTE_NONNUMERIC) {
+			PyObject *num;
+
+			num = PyNumber_Float(field);
+			if (num == NULL) {
+				quoted = 1;
+				PyErr_Clear();
+			}
+			else {
+				Py_DECREF(num);
+			}
+		}
+
+		if (PyString_Check(field)) {
+			append_ok = join_append(self, PyString_AsString(field),
+                                                &quoted, len == 1);
+			Py_DECREF(field);
+		}
+		else if (field == Py_None) {
+			append_ok = join_append(self, "", &quoted, len == 1);
+			Py_DECREF(field);
+		}
+		else {
+			PyObject *str;
+
+			str = PyObject_Str(field);
+			Py_DECREF(field);
+			if (str == NULL)
+				return NULL;
+
+			append_ok = join_append(self, PyString_AsString(str), 
+                                                &quoted, len == 1);
+			Py_DECREF(str);
+		}
+		if (!append_ok)
+			return NULL;
+	}
+
+	/* Add line terminator.
+	 */
+	if (!join_append_lineterminator(self))
+		return 0;
+
+	return PyObject_CallFunction(self->writeline, 
+                                     "(s#)", self->rec, self->rec_len);
+}
+
+static PyObject *
+csv_writerows(WriterObj *self, PyObject *seqseq)
+{
+        PyObject *row_iter, *row_obj, *result;
+
+        row_iter = PyObject_GetIter(seqseq);
+        if (row_iter == NULL) {
+                PyErr_SetString(PyExc_TypeError,
+                                "writerows() argument must be iteratable");
+                return NULL;
+        }
+        while ((row_obj = PyIter_Next(row_iter))) {
+                result = csv_writerow(self, row_obj);
+                Py_DECREF(row_obj);
+                if (!result) {
+                        Py_DECREF(row_iter);
+                        return NULL;
+                }
+                else
+                     Py_DECREF(result);   
+        }
+        Py_DECREF(row_iter);
+        if (PyErr_Occurred())
+                return NULL;
+        Py_INCREF(Py_None);
+        return Py_None;
+}
+
+static struct PyMethodDef Writer_methods[] = {
+        { "writerow", (PyCFunction)csv_writerow, METH_O, csv_writerow_doc},
+        { "writerows", (PyCFunction)csv_writerows, METH_O},
+	{ NULL, NULL }
+};
+
+#define W_OFF(x) offsetof(WriterObj, x)
+
+static struct PyMemberDef Writer_memberlist[] = {
+	{ "dialect", T_OBJECT, W_OFF(dialect), RO },
+	{ NULL }
+};
+
+static void
+Writer_dealloc(WriterObj *self)
+{
+        Py_XDECREF(self->dialect);
+        Py_XDECREF(self->writeline);
+	PyMem_DEL(self);
+}
+
+PyDoc_STRVAR(Writer_Type_doc, 
+"CSV writer\n"
+"\n"
+"Writer objects are responsible for generating tabular data\n"
+"in CSV format from sequence input.\n"
+);
+
+static PyTypeObject Writer_Type = {
+	PyObject_HEAD_INIT(NULL)
+	0,                                      /*ob_size*/
+	"_csv.writer",                          /*tp_name*/
+	sizeof(WriterObj),                      /*tp_basicsize*/
+	0,                                      /*tp_itemsize*/
+	/* methods */
+	(destructor)Writer_dealloc,             /*tp_dealloc*/
+	(printfunc)0,                           /*tp_print*/
+	(getattrfunc)0,                         /*tp_getattr*/
+	(setattrfunc)0,                         /*tp_setattr*/
+	(cmpfunc)0,                             /*tp_compare*/
+	(reprfunc)0,                            /*tp_repr*/
+	0,                                      /*tp_as_number*/
+	0,                                      /*tp_as_sequence*/
+	0,                                      /*tp_as_mapping*/
+	(hashfunc)0,                            /*tp_hash*/
+	(ternaryfunc)0,                         /*tp_call*/
+	(reprfunc)0,                            /*tp_str*/
+	0,                                      /*tp_getattro*/
+        0,                                      /*tp_setattro*/
+        0,                                      /*tp_as_buffer*/
+        Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+	Writer_Type_doc,
+        0,                                      /*tp_traverse*/
+        0,                                      /*tp_clear*/
+        0,                                      /*tp_richcompare*/
+        0,                                      /*tp_weaklistoffset*/
+        (getiterfunc)0,                         /*tp_iter*/
+        (getiterfunc)0,                         /*tp_iternext*/
+        Writer_methods,                         /*tp_methods*/
+        Writer_memberlist,                      /*tp_members*/
+        0,                                      /*tp_getset*/
+};
+
+static PyObject *
+csv_writer(PyObject *module, PyObject *args, PyObject *keyword_args)
+{
+        PyObject * output_file, * dialect = NULL, *ctor_args;
+        WriterObj * self = PyObject_NEW(WriterObj, &Writer_Type);
+
+        if (!self)
+                return NULL;
+
+        self->dialect = NULL;
+        self->writeline = NULL;
+
+	self->rec = NULL;
+	self->rec_size = 0;
+	self->rec_len = 0;
+	self->num_fields = 0;
+
+        if (!PyArg_ParseTuple(args, "O|O", &output_file, &dialect)) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->writeline = PyObject_GetAttrString(output_file, "write");
+        if (self->writeline == NULL || !PyCallable_Check(self->writeline)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "argument 1 must be an instance with a write method");
+                Py_DECREF(self);
+                return NULL;
+        }
+        ctor_args = Py_BuildValue(dialect ? "(O)" : "()", dialect);
+        if (ctor_args == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        self->dialect = (DialectObj *)PyObject_Call((PyObject *)&Dialect_Type,
+                                                    ctor_args, keyword_args);
+        Py_DECREF(ctor_args);
+        if (self->dialect == NULL) {
+                Py_DECREF(self);
+                return NULL;
+        }
+        return (PyObject *)self;
+}
+
+/*
+ * DIALECT REGISTRY
+ */
+static PyObject *
+csv_list_dialects(PyObject *module, PyObject *args)
+{
+        return PyDict_Keys(dialects);
+}
+
+static PyObject *
+csv_register_dialect(PyObject *module, PyObject *args)
+{
+        PyObject *name_obj, *dialect_obj;
+
+        if (!PyArg_ParseTuple(args, "OO", &name_obj, &dialect_obj))
+                return NULL;
+        if (!PyString_Check(name_obj) && !PyUnicode_Check(name_obj)) {
+                PyErr_SetString(PyExc_TypeError, 
+                                "dialect name must be a string or unicode");
+                return NULL;
+        }
+        Py_INCREF(dialect_obj);
+        /* A class rather than an instance? Instanciate */
+        if (PyObject_TypeCheck(dialect_obj, &PyClass_Type)) {
+                PyObject * new_dia;
+                new_dia = PyObject_CallFunction(dialect_obj, "");
+                Py_DECREF(dialect_obj);
+                if (new_dia == NULL)
+                        return NULL;
+                dialect_obj = new_dia;
+        }
+        /* Make sure we finally have an instance */
+        if (!PyInstance_Check(dialect_obj)) {
+                PyErr_SetString(PyExc_TypeError, "dialect must be an instance");
+                Py_DECREF(dialect_obj);
+                return NULL;
+        }
+        if (PyObject_SetAttrString(dialect_obj, "_name", name_obj) < 0) {
+                Py_DECREF(dialect_obj);
+                return NULL;
+        }
+        if (PyDict_SetItem(dialects, name_obj, dialect_obj) < 0) {
+                Py_DECREF(dialect_obj);
+                return NULL;
+        }
+        Py_DECREF(dialect_obj);
+        Py_INCREF(Py_None);
+        return Py_None;
+}
+
+static PyObject *
+csv_unregister_dialect(PyObject *module, PyObject *args)
+{
+        PyObject *name_obj;
+
+        if (!PyArg_ParseTuple(args, "O", &name_obj))
+                return NULL;
+        if (PyDict_DelItem(dialects, name_obj) < 0)
+                return PyErr_Format(error_obj, "unknown dialect");
+        Py_INCREF(Py_None);
+        return Py_None;
+}
+
+static PyObject *
+csv_get_dialect(PyObject *module, PyObject *args)
+{
+        PyObject *name_obj;
+
+        if (!PyArg_ParseTuple(args, "O", &name_obj))
+                return NULL;
+        return get_dialect_from_registry(name_obj);
+}
+
+/*
+ * MODULE
+ */
+
+PyDoc_STRVAR(csv_module_doc,
+"CSV parsing and writing.\n"
+"\n"
+"This module provides classes that assist in the reading and writing\n"
+"of Comma Separated Value (CSV) files, and implements the interface\n"
+"described by PEP 305.  Although many CSV files are simple to parse,\n"
+"the format is not formally defined by a stable specification and\n"
+"is subtle enough that parsing lines of a CSV file with something\n"
+"like line.split(\",\") is bound to fail.  The module supports three\n"
+"basic APIs: reading, writing, and registration of dialects.\n"
+"\n"
+"\n"
+"DIALECT REGISTRATION:\n"
+"\n"
+"Readers and writers support a dialect argument, which is a convenient\n"
+"handle on a group of settings.  When the dialect argument is a string,\n"
+"it identifies one of the dialects previously registered with the module.\n"
+"If it is a class or instance, the attributes of the argument are used as\n"
+"the settings for the reader or writer:\n"
+"\n"
+"    class excel:\n"
+"        delimiter = ','\n"
+"        quotechar = '\"'\n"
+"        escapechar = None\n"
+"        doublequote = True\n"
+"        skipinitialspace = False\n"
+"        lineterminator = '\r\n'\n"
+"        quoting = QUOTE_MINIMAL\n"
+"\n"
+"SETTINGS:\n"
+"\n"
+"    * quotechar - specifies a one-character string to use as the \n"
+"        quoting character.  It defaults to '\"'.\n"
+"    * delimiter - specifies a one-character string to use as the \n"
+"        field separator.  It defaults to ','.\n"
+"    * skipinitialspace - specifies how to interpret whitespace which\n"
+"        immediately follows a delimiter.  It defaults to False, which\n"
+"        means that whitespace immediately following a delimiter is part\n"
+"        of the following field.\n"
+"    * lineterminator -  specifies the character sequence which should \n"
+"        terminate rows.\n"
+"    * quoting - controls when quotes should be generated by the writer.\n"
+"        It can take on any of the following module constants:\n"
+"\n"
+"        csv.QUOTE_MINIMAL means only when required, for example, when a\n"
+"            field contains either the quotechar or the delimiter\n"
+"        csv.QUOTE_ALL means that quotes are always placed around fields.\n"
+"        csv.QUOTE_NONNUMERIC means that quotes are always placed around\n"
+"            fields which contain characters other than [+-0-9.].\n"
+"        csv.QUOTE_NONE means that quotes are never placed around fields.\n"
+"    * escapechar - specifies a one-character string used to escape \n"
+"        the delimiter when quoting is set to QUOTE_NONE.\n"
+"    * doublequote - controls the handling of quotes inside fields.  When\n"
+"        True, two consecutive quotes are interpreted as one during read,\n"
+"        and when writing, each quote character embedded in the data is\n"
+"        written as two quotes\n");
+
+PyDoc_STRVAR(csv_reader_doc,
+"    csv_reader = reader(iterable [, dialect='excel']\n"
+"                        [optional keyword args])\n"
+"    for row in csv_reader:\n"
+"        process(row)\n"
+"\n"
+"The \"iterable\" argument can be any object that returns a line\n"
+"of input for each iteration, such as a file object or a list.  The\n"
+"optional \"dialect\" parameter is discussed below.  The function\n"
+"also accepts optional keyword arguments which override settings\n"
+"provided by the dialect.\n"
+"\n"
+"The returned object is an iterator.  Each iteration returns a row\n"
+	     "of the CSV file (which can span multiple input lines):\n");
+
+PyDoc_STRVAR(csv_writer_doc,
+"    csv_writer = csv.writer(fileobj [, dialect='excel']\n"
+"                            [optional keyword args])\n"
+"    for row in csv_writer:\n"
+"        csv_writer.writerow(row)\n"
+"\n"
+"    [or]\n"
+"\n"
+"    csv_writer = csv.writer(fileobj [, dialect='excel']\n"
+"                            [optional keyword args])\n"
+"    csv_writer.writerows(rows)\n"
+"\n"
+"The \"fileobj\" argument can be any object that supports the file API.\n");
+
+PyDoc_STRVAR(csv_list_dialects_doc,
+"Return a list of all know dialect names.\n"
+"    names = csv.list_dialects()");
+
+PyDoc_STRVAR(csv_get_dialect_doc,
+"Return the dialect instance associated with name.\n"
+"    dialect = csv.get_dialect(name)");
+
+PyDoc_STRVAR(csv_register_dialect_doc,
+"Create a mapping from a string name to a dialect class.\n"
+"    dialect = csv.register_dialect(name, dialect)");
+
+PyDoc_STRVAR(csv_unregister_dialect_doc,
+"Delete the name/dialect mapping associated with a string name.\n"
+"    csv.unregister_dialect(name)");
+
+static struct PyMethodDef csv_methods[] = {
+        { "reader", (PyCFunction)csv_reader, 
+            METH_VARARGS | METH_KEYWORDS, csv_reader_doc},
+        { "writer", (PyCFunction)csv_writer, 
+            METH_VARARGS | METH_KEYWORDS, csv_writer_doc},
+        { "list_dialects", (PyCFunction)csv_list_dialects, 
+            METH_NOARGS, csv_list_dialects_doc},
+        { "register_dialect", (PyCFunction)csv_register_dialect, 
+            METH_VARARGS, csv_register_dialect_doc},
+        { "unregister_dialect", (PyCFunction)csv_unregister_dialect, 
+            METH_VARARGS, csv_unregister_dialect_doc},
+        { "get_dialect", (PyCFunction)csv_get_dialect, 
+            METH_VARARGS, csv_get_dialect_doc},
+        { NULL, NULL }
+};
+
+PyMODINIT_FUNC
+init_csv(void)
+{
+	PyObject *module;
+	PyObject *rev;
+	PyObject *v;
+	int res;
+	StyleDesc *style;
+
+	if (PyType_Ready(&Dialect_Type) < 0)
+		return;
+
+	if (PyType_Ready(&Reader_Type) < 0)
+		return;
+
+	if (PyType_Ready(&Writer_Type) < 0)
+		return;
+
+	/* Create the module and add the functions */
+	module = Py_InitModule3("_csv", csv_methods, csv_module_doc);
+	if (module == NULL)
+		return;
+
+	/* Add version to the module. */
+	rev = PyString_FromString("1.0");
+	if (rev == NULL)
+		return;
+        if (PyModule_AddObject(module, "__version__", rev) < 0)
+		return;
+
+        /* Add _dialects dictionary */
+        dialects = PyDict_New();
+        if (dialects == NULL)
+                return;
+        if (PyModule_AddObject(module, "_dialects", dialects))
+                return;
+
+	/* Add quote styles into dictionary */
+	for (style = quote_styles; style->name; style++) {
+		v = PyInt_FromLong(style->style);
+		if (v == NULL)
+			return;
+		res = PyModule_AddObject(module, style->name, v);
+		if (res < 0)
+			return;
+	}
+
+        /* Add the Dialect type */
+        if (PyModule_AddObject(module, "Dialect", (PyObject *)&Dialect_Type))
+                return;
+
+	/* Add the CSV exception object to the module. */
+	error_obj = PyErr_NewException("_csv.Error", NULL, NULL);
+	if (error_obj == NULL)
+		return;
+	PyModule_AddObject(module, "Error", error_obj);
+}